Interesting that you note FreeCiv – whatever I’m doing, it just doesn’t seem to have the same gravitas as Civ II, which my sister and I grew up playing. I also found that… well, it’s a huge timesink! With me, I find that it just induces this odd sense of wondering what’s going to happen next while also remaining fairly confident that nothing too pressing is going to come up. That said, I do like the game (currently playing on Linux), but I’ve been trying to occupy my time with things more worthwhile.
…On the bright side, it’s most certainly a free game with lots of drop-in tilesets, etc. If there’s one truly fond memory of the game it was back in my Windows Vista days. The AI made HORDES of howitzers which my air force was desperately bombing as they crossed the mountains! I must not be paying good attention to the game settings, as I’ve not seen that kind of insanity since getting it on my distro.
As per scenarios, I do believe there are medieval scenarios in the game, but I’m not sure how those work. The base game makes doing anything of note in the ancient period kind of moot – the time passes so rapidly. Civ II did that as well but the ancient warfare was definitely more pronounced.